Variation in Operational Objectives and Associated Biophysical Effects, with Focus on Northern New England Mike Burke, Nick Nelson, and Kristen Coveleski Motivations • Explore dam operations and associated biophysical effects • Explore regional trends in dam operational objectives and characteristics • Review selected screening-level tools for assessing potential for impacts. Outline • Concepts of Operational Effects • Regional Trends • Case Study Operational Effects Adapted from Burke et al. 2009 Operational Effects Source: Grant et al. 2003 Source: Poff et al. 1997 Regional Trends • Active Dams • Maine: 616 • New Hampshire: 2615 • Vermont: 650 Data from most recent online dam safety data GIS coverages for each state. Regional Trends • Active Dams • Maine: 616 • New Hampshire: 2615 • Vermont: 650 ME NH VT Hydropower 82 119 85 Water Supply 64 66 41 Flood Control664615 Recreation 229 1215 277 Other 175 1169 232 Detention 251 Conservation/Ag 635 Fire Protection 200 Regional Trends • Active Dams • Maine: 616 • New Hampshire: 2615 • Vermont: 650 ME NH VT Hydropower 82 119 85 Water Supply 64 66 41 Flood Control664615 Recreation 229 1215 277 Other 175 1169 232 Detention 251 Conservation/Ag 635 Fire Protection 200 Regional Trends Height ME NH VT 0‐25 161 146 70 26‐50 39 55 43 50‐100 10 25 14 101‐150 2 5 5 151‐260 1 2 5 Case Study • West River, Vermont • 423 mi2 tributary to the Connecticut • Flood Control Act 1961 • Ball Mountain Dam • 93,000 Ac Ft Storage • 260 ft height • 172 mi2 • Townshend Dam • 56,000 Ac Ft Storage • 133 ft height • 278 mi2 Case Study Ball Mountain Dam Townshend Dam Case Study – hydrologic effects Below Ball Mountain Dam Below Townshend Dam W est River Jamaica W est River Newfane Pre Post Ratio Pre Post Ratio Monthly Medians October 60.5 154.0 2.55 114.0 160.0 1.40 November 152.0 229.3 1.51 249.3 349.3 1.40 December 185.5 250.5 1.35 283.0 377.5 1.33 January 155.0 170.0 1.10 275.0 245.0 0.89 February 172.5 180.0 1.04 240.0 305.3 1.27 March 300.0 294.0 0.98 590.0 456.5 0.77 April 1093.0 958.8 0.88 1823.0 1773.0 0.97 May 354.0 356.5 1.01 623.0 688.0 1.10 June 118.5 135.0 1.14 217.0 195.8 0.90 July 48.0 68.0 1.42 92.0 107.0 1.16 August 32.0 50.5 1.58 61.5 89.5 1.46 September 30.8 45.5 1.48 71.5 88.5 1.24 Annual Medians 1-day minimum 10.5 23.5 2.24 25.0 41.0 1.64 3-day minimum 10.8 25.2 2.32 26.2 42.2 1.61 7-day minimum 12.5 28.9 2.31 29.8 44.8 1.50 30-day minimum 20.1 40.8 2.03 49.7 68.8 1.39 90-day minimum 65.6 90.9 1.39 116.8 135.3 1.16 1-day maximum 5835.0 3715.0 0.64 8265.0 5820.0 0.70 3-day maximum 4382.0 3150.0 0.72 6103.0 5340.0 0.87 7-day maximum 3002.0 2447.0 0.82 4549.0 4394.0 0.97 30-day maximum 1755.0 1474.0 0.84 2750.0 2835.0 1.03 90-day maximum 895.2 831.7 0.93 1506.0 1515.0 1.01 Case Study – hydrologic effects W est River Jamaica W est River Newfane Ball Mountain Storage 93000 Ac Ft Ball Mountain Storage 93000 Ac Ft Townshend Storage 56000 Ac Ft Combined Storage 149000 Ac Ft Storage/MAF 0.34 Storage/MAF 0.12 Cummulative Storage/MAF 0.32 2 2 Sediment Basin (mi ) 172 Sediment Basin (mi ) 278 Sediment Basin (%/total) 0.41 Sediment Basin (%/total) 0.66 Pre Post Ratio Pre Post Ratio Max Peak 29500 5900 0.20 52,300 10,300 0.20 Median Peak 8565 4320 0.50 12,200 6,685 0.55 Min Peak 4070 2420 0.59 4,810 3,700 0.77 Mobile Size Median Peak 4.6 3.2 0.69 1.3 1.0 0.72 MAF: Mean Annual Flow Case Study – comparisons between larger dams and with other regions Name River Height (ft) Storage (Ac‐ft) Storage/MAF MAF/mi2 Ripogenus WB Penobscot 180 698850 0.26 1.8 Wyman Kennebec 140 649936 0.20 1.7 Ball Mountain West River 260 93000 0.34 2.1 Townshend West River 133 56000 0.12/0.34 2.2 Platte 0.04 Colorado 0.15 Snake (Hells Canyon) 0.3 Columbia 1 Kootenai (Libby) 1.4 Willamette 2.5 Alaskan Rivers >2.5 MAF: Mean Annual Flow Questions Thank You! Mike Burke [email protected] 207.563.1332 Citations Burke, M., Jorde, K., & Buffington, J., 2009. Application of a hierarchical framework for assessing environmental impacts of dam operation: changes in streamflow, bed mobility and recruitment of riparian trees in a western North American river. Journal of Environmental Management, 90: 224–236. Grant, G. E., J. C. Schmidt, and S. L. Lewis. 2003. A Geological Framework for Interpreting Downstream Effects of Dams on Rivers. Pages 209-225 in A Unique River. American Geophysical Union. MEGIS 2006. IMPOUNDS GIS database of dams in State of Maine compiled by Office of Dam Safety. http://www.maine.gov/megis/catalog/metadata/impounds.htm NHDES 2015. DAMSNH GIS database of dams in State of New Hampshire registered with Department of Environmental Services. http://des.nh.gov/onestop/documents/dams-metadata.pdf Poff, N. L., J. D. Allan, M. B. Bain, J. R. Karr, K. L. Prestegaard, B. D. Ricther, R. E. Sparks, and J. C. Stromberg. 1997. The Natural Flow Regime. Bioscience 47:769-784. VDNR 2015. DAMS GIS database of dams in State of Vermont. http://dware.vcgi.org/search_tools/moreinfo.cfm?catalog_id=6&layer_id=20142&layer_name=WaterOthe r_DAMS.